SAN FRANCISCO — Twitter is rolling out two new features designed to make the service easier to use and more appealing: private group messaging and the ability to shoot, edit and post videos directly through the Twitter app.

The company is adding the new features as it attempts to reassure investors about its growth prospects following a turbulent first year as a publicly traded company.

Twitter, which says its ambition is to build "the largest daily audience in the world," is hoping to get more people to use the service and to get the people already using the service to engage with it more frequently.

It recently introduced a new "while you were away" feature that highlights important tweets that were posted while a user was offline.

"We feel investor sentiment ... remains largely negative," Robert Peck, managing director and Internet equity analyst at SunTrust Robinson Humphrey, said in a recent report. "The majority of investors we speak with continue to have concerns over the long term story for monetization and (monthly active users) growth."

But some analysts believe new features, investments in advertising technology and the company's outreach to third-party software developers could be "potential catalysts" for Twitter having a "Facebook moment" in 2015, Peck said.

Twitter reports fourth-quarter earnings on Feb. 5.

Twitter's new in-app video feature(Photo: Twitter)

Both video and group messaging have been extremely popular on other services such as Facebook and have been frequently requested by Twitter users.

Video may be one of the most important new features that Twitter has introduced in some time.

Before Tuesday, the only way for most Twitter users to share video was through Vine, Twitter's standalone video app. (Last year, the company rolled out a video unit for a small group of verified users and advertisers that lets them upload videos up to 10 minutes in length on the Web.)

Now with a few taps, Twitter users can add video up to 30 seconds in length. Twitter for iPhone users can upload videos from the camera roll as well. That feature is coming soon to Android, the company said.

"We think by arming all these people with video, we are going to get some really rich and engaging content in the network every day that users are going to love," said Jinen Kamdar, a Twitter product director.

The new group messaging feature taps into the growing popularity of messaging apps. It lets users start conversations with up to 20 people on Twitter. Those people don't all have to follow each other to chat privately.

Twitter is a service mostly focused on public conversations. But now it's investing in private conversations as well, Kamdar said. Many of the topics people explore in public on Twitter are "conversation starters" for small groups of Twitter users, he said.

Twitter users can save and name their groups. Anyone in the group can rename the group. One Twitter employee has a family group which she named "family." Her sister renamed it "ignore."

Both features began rolling out Tuesday and should be in users' hands in the next couple of weeks.